Gross mortgage lending jumped by 13.3% annually to £20.4bn last month, while approvals were 11% higher, year-on-year.
The increase is largely down to a 30% annual increase in remortgage approvals, the data showed.
Mark Harris, chief executive of mortgage broker SPF Private Clients, said: “We are witnessing a highly competitive remortgage market.
“Lenders are seeking to increase market share, often providing additional incentives to borrowers remortgaging, including free survey and legal packages.
“The mortgage market is oversupplied which will continue to drive down lender margins and pricing, which is great for borrowers.”
Eric Leenders, managing director of personal finance at UK Finance added: “April saw steady growth in mortgage lending and approvals, following a slowdown in activity the previous month.
“This was driven by strong remortgaging levels, as borrowers locked into attractive deals amid expectations of a base rate rise.”